FIG. 1 shows an electrode pattern of a conventional surface discharge plasma display panel. FIG. 2 is a schematic sectional view of a pixel of FIG. 1. Referring to FIGS. 1 and 2, the conventional surface discharge plasma display panel includes address electrodes A1, A2, A3, . . . , Am, a first dielectric 21, a luminescent material 22, scan electrodes Y1, Y2, . . . , Yn-1, Yn, 231, 232, common electrodes X, 241, 242, a second dielectric 25, and a protective layer 26. Each of the scan electrodes Y1, Y2, . . . , Yn-1, Yn, includes an indium tin oxide (ITO) scan electrode 231 and a bus scan electrode 232. In the same manner, each of the common electrodes X, 241, 242 includes a common ITO electrode 241 and a common bus electrode 242. Gas for forming plasma is sealed between the protective layer 26 and a first dielectric 21.
The address electrodes A1, A2, A3, . . . , Am are coated on a lower substrate (not shown) of a first substrate in a predetermined pattern. The first dielectric 21 is coated on the address electrodes A1, A2, A3, . . . , Am. The luminescent material 22 is coated on the first dielectric 21 in a predetermined pattern. Depending on circumstances, without forming the first dielectric 21, the luminescent material 22 may be coated on the address electrodes A1, A2, A3, . . . , Am, in a predetermined pattern. The scan electrodes Y1, Y2, . . . , Yn-1, Yn, 231, 242 and the common electrodes X, 241, 242 are formed on an upper substrate (not shown) of a second substrate, such that they intersect with the address electrodes A1, A2, A3, . . . , Am. The respective intersections each define a corresponding pixel. The second dielectric 25 is coated on the scan electrodes Y1, Y2, . . . , Yn-1, Yn, 231, 232 and the common electrodes X, 241, 242. The protective layer 26 for protecting the panel from a strong electrical field is coated on the second dielectric 25.
In the prior art driving method of a surface discharge plasma display panel, a relatively high voltage is applied between the scan electrodes Y1, Y2, . . . , Yn-1, Yn, 231, 232 and the common electrodes X, 241, 242 to accumulate wall charges in the respective pixel by a surface discharge, and the wall-charges accumulated by the surface discharge are removed, in a resetting step. The conventional driving method is disclosed in U.S. Pat. No. 5,446,344.
FIG. 3 depicts a conventional driving method of a surface discharge plasma display panel.
In a first reset interval (a-b), a pulse of voltage Vaw, a pulse of voltage Vs+Vw, and 0 V are applied to the address electrodes Am, the common electrodes X, and the scan electrodes Y1, Y2, . . . , Yn, respectively. Here, the voltage Vs+Vw obtained by adding the voltage Vw to the scan voltage Vs is higher than the voltage Vaw. Accordingly, a relatively high voltage Vs+Vw is applied between the common electrodes X and the scan electrodes Y1, Y2, . . . , Yn, so that a surface discharge occurs between the common electrodes X and the scan electrodes Y1, Y2, . . . , Yn (`a` of FIG. 3). Positive (+) wall-charges are accumulated in the positive layer 26 of FIG. 2 under each of the scan electrodes 231, 232 of FIG. 2, and negative(-) wall-charges are accumulated in the positive layer 26 under the common electrodes 241, 242 of FIG. 2.
The voltage of the wall-charges accumulated during the first reset interval (a-b) is a re-dischargeable voltage. In a second reset interval (b-c), 0 V is applied to the address electrodes Am, the common electrodes X, and the scan electrodes Y1, Y2, . . . , Yn. Accordingly, due to the wall-charges accumulated during the first reset interval (a-b), a surface discharge occurs between the common electrodes X and the scan electrodes Y1, Y2, . . . , Yn. The wall-charges of all pixels then removed.
In an address step, in a state in which a pulse of voltage Vax is applied to the common electrodes X, scan pulses of a voltage -Vy are sequentially applied to each of the scan electrodes Y1, Y2, . . . , Yn. When the scan pulse is not applied, a negative voltage-Vsc which is a level lower than the voltage -Vy of the scan pulse is applied. When a pulse of the address voltage Va is applied to an address electrode Am selected while the scan pulse is applied to a scan electrode Y1, Y2, . . . , Yn, for example, during interval (c-d) for the scan electrode Y1, a facing discharge is performed in a corresponding pixel. This is because a voltage for facing discharge Va+Vy is applied between the corresponding scan electrode Y1, Y2, . . . , or Yn and the selected address electrode Am. At this time, when a negative voltage -Vsc which is lower than the voltage -Vy of the scan pulse is applied, the facing discharge stops. Positive(+) wall-charges are than accumulated under the scan electrodes 231, 232 of the selected pixel.
In a first sustaining discharge interval (g-h), a pulse of the voltage Vs/2 which is 1/2 the scan voltage Vs, 0V, and a pulse of the sustaining discharge voltage Vs, are applied to the address electrodes Am, the common electrode X, and the scan electrodes Y1, Y2, . . . , Yn, respectively. That is, in a state in which positive(+) wall-charges are accumulated under the scan electrode Y1, Y2, . . . , or Yn of the selected pixel, when a relatively high negative-voltage is applied between the scan electrodes Y1, Y2, . . . , Yn and the common electrodes X, a surface discharge occurs in the selected pixel. When the surface discharge is performed in the selected pixel, plasma is formed in a gas layer of a corresponding region, and a luminescent material 22 of FIG. 2 is excited by an UV-ray to emit light.
In a second sustaining discharge interval (i-j), a a pulse of the voltage Vs/2 which is 1/2 the scan voltage Vs, and pulse of the sustaining discharge voltage Vs, and 0V, are applied to the address electrodes Am, the common electrodes X, and the scan electrodes Y1, Y2, . . . , Yn, respectively. That is, in a state in which wall-charges are accumulated, when a relatively high negative voltage is applied between the scan electrodes Y1, Y2, . . . , Yn and the common electrodes X, a surface discharge occurs in a selected pixel. Positive(+) wall-charges are then accumulated under the scan electrodes 231, 232 of the selected pixel, and negative(-) wall-charges are accumulated under the common electrodes 241, 242. When the surface discharge is performed in the selected pixel, plasma is formed in a gas layer of a corresponding region, and a luminescent material 22 is excited by a UV-ray to emit light. The operations of the first and second sustained discharge intervals are repeated during the sustaining discharge period, to thereby maintain the emission of light at the selected pixel.
In the conventional driving method, in the resetting step (interval a-c of FIG. 3), a pulse of a relatively high voltage Vs+Vw is applied between the common electrodes X and the scan electrodes Y1, Y2, . . . , Yn, so that a surface discharge occurs. Accordingly, the light of relatively high brightness is emitted from the unselected pixels, to thereby decrease the contrast of a display screen.